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Relating FFT magnitude to dBSPL
Hello, please know I am a member of the public, not a student.

I use the Acceleration Spectrum feature of phyphox to monitor infrasound and low-frequency vibration (0.78 - 30 Hz at 5 - 72 dBSPL) happening constantly in my home and the surrounding geographic area. The source is unknown and I am collecting data to help me find where or what it's coming from.

I have some technical background in telephony and data networking but none in signal analysis or advanced mathematics. I hope nobody feels insulted that I ask here for help.

Before I found phyphox, I used another free app called Infrasound Detector that was much simpler -- in fact, too simple.  I read online about infrasound and wave mechanics, and want to collect better information about the 'signal' that is more accurate and more credible. I was happy to find phyphox!  Shy

However, I don't know how to interpret the signal magnitude shown by the Fast Fourier Transform in phyphox [FFT Mag. (a.u.)], or ANY of the readings on the Raw Data page.  Undecided

The other app (Infrasound Detector) gave readings expressed as frequency (Hz) and intensity (dBSPL).  It would help me VERY MUCH to be able to understand the phyphox magnitude readings in terms of these units of measure.

Or, is there a different app that might suit my purpose better, instead of phyphox? I doubt it but thought I should ask.  I want to respect everybody's time on this forum as well as find an answer for my need.

I'm very grateful for whatever help or advice I receive on this topic.  Thank you in advance!

Catherine Julian
USA (Washington State)

Messages In This Thread
Relating FFT magnitude to dBSPL - by Catherine Julian - 11-21-2020, 10:34 PM

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